Tooth cutting machine with work handling mechanism



Nov. 28, 1967 w. G. BUCHANAN ET 3,354,782

TOOTH-CUTTING MACHINE WITH WORK HANDLING MECHANISM Original Filed April2, 1964 '9 Sheets-Sheet 1 FIG. I

INVENTORS WILLIAM G. BUCHANAN GEORGE H. HOWING am/um ATTORNEY Nov. 28,1967 w. G. BUCHANAN ET AL 3,354,782

TOOTH CUTTING MACHINE WITH WORK HANDLING MECHANISM Original Filed April2, 1964 9 Sheets-Sheet 2 Nov. 28, 1967 w, BUCHANAN ET AL 3,354,782

TOOTH CUTTING MACHINE WITH WORK HANDLING MECHANISM Original Filed April2, 1964 9 Sheets-Sheet 5 Nov. 28, 1967 w. G. BUCHANAN ET AL 3,354,782

TOOTH CUTTING MACHINE WITH WORK HANDLING MECHANISM Original Filed April2, 1964 9 Sheets-Sheet Nov. 28, 1967 w. G. BUCHANAN ET AL 3,354,782

TOOTH CUTTING MACHINE WITH WORK HANDLING MECHANISM 9 Sheets-Sheet 5Original Filed April 2, 1.964

Nov. 28, 1967 w. e. BUCHANAN ET 3,354,782

TOOTH CUTTING MACHINE WITH WORK HANDLING MECHANISM Original Filed April2, 1964 9 Sheets-$heet 6 J A n' ;%a ,6

Y H i Nwzs, 1967 HANAN ETAL '3,354,7s2

TOOTH CUTTING MACHINE WITH WORK HANDLING MECHANISM Original Filed April2, 1964 9 Sheets-Sheet 7 I9 I64 I92 9 4 192/ FIG. 16'

Nov. 28, 1967 w. G. BUCHANAN E AL 3,354,782

TOOTH CUTTING MACHINE WITH WORK HANDLING MECHANISM Original Filed April2, 1964 9 Sheets- Sheet 8 FIG. 2|

Nov. 28, 1967 w. G. BUCHANAN ET AL 3,354,782

TOOTH CUTTING MACHINE WITH WORK HANDLING MECHANISM Original Filed April2, 1964 9 Sheets-Sheet 9 FIG. 23

, 3,354,782 Patented Nov. 28, 1967 3,354,782 TOOTH CUTTENG MACHINE WITHWORK HANDLING MECHANHSM William G. Buchanan and George H. Howing,Rochester, N.Y., assignors to The Gleason Works, Rochester, N.Y., acorporation of New York Continuation of application Ser. No. 356,711,Apr. 2, 1964. This application Mar. 24, 1966, Ser. No. 537,243 10tClaims (Ci. 901) ABSTRACT F THE DISCLOSURE A bevel gear cutting machinehas an endless chain conveyor with work holders for transferring workgears from a first carrier, which loads and unloads the work spindle ata rough cutting station at one side of the machine, to a second carrierwhich loads and unloads the work spindle at a finish cutting station onthe other side of the machine. A pair of ratcheting actuators, connectedfor simultaneous operation, act on the conveyor at points near therespective carriers. Both carriers have reciprocating and angularmotion, and have work supporting recesses on their peripheries. Astationary cam ejects the gears from the recesses of the carrier at thefinishing station. The conveyor is guided along inner and outer U-shapedpaths which extend along the two sides and the back of the machine, andhave the open ends of their U-shapes joined by semicircular pathportions adjacent the carriers. The conveyor guide means are adjustableto enable simultaneous registration of the Work holders with bothcarriers, and include guide sections which have articulated connectionsto accommodate reciprocation of a slide on which the finishing stationcarrier and the work spindle are mounted.

This is a continuation of application Ser. No. 356,711, filed Apr. 2,1964 and now abandoned. The invention relates to a tooth cuttingmachine, especially of the kind disclosed in co-pending application Ser.No. 337,121 filed Jan. 7, 1964 by Thomas A. Deprez et al., now PatentNo. 3,229,585, granted Jan. 18, 1966 and relates particularly to animproved work handling mechanism of such machine.

The machine disclosed in said co-pending application has a pair ofcutters adapted respectively to rough and finish cut workpieces that arechucked on indexing work spindle adjacent the cutters. The object of theinvention is a simple and inexpensive yet reliable mechanism fordelivering workpieces to the roughing work spindle, transferring roughedworkpieces from the roughing work spindle to the finishing work spindle,and discharging the finished workpieces. A related object is a mechanismin which blank and roughed workpieces are held ready to be placed on thework spindles as soon as workpieces cut in the preceding cutting cycleare removed from these spindles. Other objects are a mechanism whichwill accurately register with the work spindles of the machine and yetwill accommodate the cutting motions and adjustments required of themachine, including reciprocation of the finishing work spindle to strokea workpiece thereon past the finishing cutter, and adjustment of thework spindles to accommodate variation in cutter diameters.

The foregoing and other objects and advantages of the invention willappear from the following description of the preferred embodiments shownin the accompanying drawings, wherein:

FIG. 1 is a fragmentary plan view of the machine;

FIG. 2 is an end view of the machine, from the left in FIG. 1;

FIG. 3 is a side View, partly in vertical section, of a work carrieradjacent the roughing work spindle and the actuator for the carrier;

FIG. 4 is a plan view of the carrier, partly in horizontal section;

FIGS. 5, 6 and 7 are detail views, respectively in planes 55, 6-6 and7-7 of FIG. 3;

FIG. 8 is an isometric view of a portion of an endless flexibleconveyor, one of the work supports carried thereby, and supporting guidestructure;

FIG. 9 is a detail plan sectional view illustrating means for adjustingthe tension of the endless conveyor;

FIGS. 10 and 11 are isometric views of the conveyor actuatorsrespectively adjacent the roughing and the finishing work spindles;

FIG. 12 is a sectional view in plane 12-12 of FIG. 1 through awork-supporting center and actuating means therefor; 1 1

FIG. 13 is a diagram of the control system of the work-handlingmechanism of the machine;

FIG. 14 is a fragmentary plan view of a modification of the machine, forproducing bevel gears having axial bores;

FIG. 15 is a plan view, on a large scale, of a work carrier shown inFIG. 14;

FIG. 16 is a vertical section in plane 1616 of FIG. 15;

FIG. 17 is a side view of the actuator for the work carrier shown inFIGS. 14 and 15;

FIG. 18 is a bottom plan section in plane 1818 of FIG. 17;

FIG. 19 is developments of cams shown in FIGS. 3 and 17;

FIG. 20 is a detail isometric view, similar to FIG. 8, of the conveyorguide and work holder structure shown in FIG. 14;

FIG. 21 is a detail vertical sectional view of means for stripping workgears from the work carrier of FIGS. 14 to 16; and

FIGS. 22 and 23 are respectively plan and side views of a mechanism forcoarse stock dividing roughed gears.

The machine comprises a frame 1 rigidly supporting a housing 2 in whicha cutter spindle is continuously rotatable about horizontal axis 3, thisspindle having secured to its opposite ends disc-shaped roughing cutterC-1 and finishing cutter 0-2 each of which cuts in successive toothslots in a workpiece on successive revolutions thereof. The cutters havegaps, not shown, between the last and first blades thereof, and eachtime these gaps come abreast of the work, the latter is indexed aboutits rotation axis to bring a successive tooth space into cuttingposition, without wihdrawing the work from the cutters.

The workpieces W in the first embodiment to be described are steeringgear sectors with shanks at both ends thereof. They are chucked forroughing on a work spindle 4 which is journaled in a work head 5 forindexing rotation about its axis 6. This axis lies in the median planeof rotation of cutter C-1 and, in the work loading-unloading position ofspindle 4, is vertical, while in cutting position, shown in FIG. 1, isslightly inclined, by a rotation of the work head about horizontal axis7 which advances the work to the roughing cutter. The work head 5 ispivoted on axis 7 to a slide 8 which is adjustable horizontally andvertically, in directions perpendicular to axes 3 and 7, on a column 9,to accommodate cutters C-1 of different diameters and workpieces ofdifferent designs. For finish cutting the workpieces are chucked on awork spindle 10 whose axis 11 lies in the median plane of rotais tion ofcutter C-2. This spindle is journaled for indexing rotation in work head12 which is pivoted to vertical slide 13 on horizontal axis 14 to enablemotion of axis 11 between a vertical position, for loading and unloadingof the work, and an inclined position in which the work is cut. Slide 13is vertically adjustable to accommodate work- .pieces of differentdesigns and is also vertically reciprocable on column 9 in time withcutter rotation. The column is adjustable horizontally on frame 1, alongWays 15, to accommodate work of difierent designs and variations incutter diameter. The mechanisms for effecting the relative adjustmentsand the machine motions so far described may be substantially asdisclosed in the aforementioned co-pending application.

In the first embodiment, illustrated in FIGS. 1 to 13, the workpieces Ware manually or otherwise loaded onto work holders 16 on anendlessflexible conveyor 17 which advances stepwise to deliver them to stationI of a carrier 18 adjacent roughing spindle 4. This carrier indexes by90 increments about its vertical axis 19 to successively carry theworkpieces to cutting station II where they are chucked on spindle 4,then, after cutting and dechucking, to idle station III, and finally todischarge station IV. Here they are received by work holders 21 ofanother endless flexible conveyor 22 which is of generally U- shape inplan, and extends along both sides and the back of column 9. By stepwiseadvance this conveyor delivers the workpieces to station I of a carrier23 adjacent finishing spindle 10. This carrier, similar to carrier 18,advances the workpieces successively about axis 24 to idle station II,then to cutting station III where they are chucked on spindle 10, andfinally, after finish cutting and dechucking, to station IV where theyare ejected into a discharge chute 25.

The carrier 18, FIGS. 1 to 4, is of substantially disc shape, with fourequi-spaced recesses 26 in the periphery thereof for receiving theshanks of the workpieces W. De tents .27, slidably retained in slots inthe edge of the disc by pins 28, are urged by springs 29 into engagementwith the workpiece shanks. The springs are retained by blocks 31 pinnedin the slots. The detents grip the workpieces with suflicient pressureto hold them firmly in the carrier during vertical motion and rotationof the latter, but yield to permit their intentional removal.

The carrier is secured to a shaft 32 that is journaled for rotation andaxial reciprocation, about and along its axis 19, in a housing 33 thatis mounted on a bracket 34, FIG. 1, on slide 8. For effecting thereciprocation a barrel cam 35 is mounted on a shaft 36 in the housing,the cam engaging a follower roller 37 carried by a member 38 that isconfined between collars 39 on shaft 32. Member 38 also carries a roller41 engaged in a straight vertical guide slot 42 in housing 33, whichserves to hold the member against rotation about axis 19. For effectingintermittent rotation of the carrier and its shaft 32 through incrementsof 90, there is a Geneva drive, FIGS. 3 and 5, comprising driver 43 onshaft 36 and driven wheel 44 keyed for axial motion to shaft 32. Thedriver has a pin 45 which on successive turns of shaft 36 enterssucceeding radial slots 46 in the driven wheel and advances the latterby a quarter-turn. An arcuate flange 47 on the driver 43 enters notchesin a peripheral flange 48 on the driven wheel as the pin 45 leaves eachslot 46, and leaves the notch as the pin enters the next slot, so thatthe wheel is at no time free of the driver. The angullar position ofcarrier 18 is closely controlled by engagement of a vertical pin 49 inone of four close fitting bores 51 which are provided at equally spacedintervals around a disc 52 secured to the upper end of shaft 32.

The phase relation between cam 35 and the Geneva drive 43, 44, is suchthat on each turn of shaft 36, the following actions occur: Cam 35 liftsthe carrier 18. At this time the carrier grips workpieces which theupwardly moving carrier strips from the holder 16 of conveyor 17 atstation I and from the work spindle 4 at station 11;

and the disc 52 disengages pin 49. The Geneva drive then rotates thecarrier through clockwise in FIGS. 1 and 4 and counterclockwise in FIG.5; and cam 35 then lowers the carrier. This engages pin 49 in a bore 51,places the blank workpiece now at station I on spindle 4 and the roughedworkpiece now at station IV onto a holder 21 of conveyor 22.

Shaft 36 is driven, intermittently and unidirectionally, by a piston incylinder 53, FIGS. 1 and 2, connected by rod 54 to rack 55 which meshesa pinion 56. The pinion is rotatable on shaft 36, clockwise in FIGS. 1and 6, but imparts counterclockwise motion to the shaft through aspring-backed clutch dog 57 which is engageable in a clutch recess 58 inthe hub of the pinion. On each stroke of the piston, to the right inFIG. 1, the shaft 36 is turned counterclockwise by one complete turn,while on each return stroke of the piston, rack 55 and pinion 56 returnfree of shaft 36. The shaft is held against such return by aspring-backed pawl 59, FIGS, 3 and 7, which is slidably supported byhousing 33 and engages in a recess 60 in driver 43 at the end of eachturn of the latter.

Carrier 23 is operated in substantially the same manner as carrier 18,by a mechanism contained in a housing 33' mounted on bracket 61 onvertical slide 13, this mechanism being substantially like that inhousing 33, and being actuated by a piston in cylinder 53' through apiston rod 54' and rack 55 simultaneously with operation of the pistonin cylinder 53. On each reciprocation of rack 55', the carrier 23 isreciprocated axially and advanced angularly, clockwise in FIG. 1, tocarry workpieces successively from receiving station I, to idle stationII, then to cut-ting station III and finally to discharge station IV. Asthe latter is approached a stationary cam 62 on housing 33 cams theworkpiece out of the carrier, from which it drops into chute 25.

The endless flexible conveyor 22 comprises a chain of vertically pivotedlinks 63 of which uniformly spaced links 63' carry supports 64, FIGS. 2and 8, for work holders 21. The conveyor runs in a substantiallyhorizontal path around guide discs 65 and 66, FIG. 1, respectivelyadjacent carriers 18 and 23, guide discs 67 and 68, and armate guideshoes 69 and 70. Accordingly the conveyor comprises an inner section ofU-shaped in plan extending from disc 65 around discs 67 and 68 to disc66, and further comprises an outer section, also of U-shape, extendingfrom disc 66 around shoes 70 and 69 to disc 65. The inner section isregarded as being the forward section since it carriers workpiece fromcarrier 18 on to carrier 23, whereas the outer section is the returnsection, which returns empty work holders 21 to the carrier 18. Asshown, the legs of the U-shapes between disc 65 and the disc and shoe67, 69, and between disc 66 and disc and shoe 68, 70, extend alongopposite sides of column 9, and are connected by the arcuate portions ofthe U-shapes which extend 90 around the discs 67, 68, and the shoes andwhich connect the legs of the U to the substantially straight basesthereof which extend along the back of the column, between discs 67, 68and between shoes 69, 70.

The conveyor is partially housed within and supported by a plurality ofbox-like guide sections, which, considered together, are ofsubstantially U-shape in plan, FIG. 1. As shown in FIGS. 1 and 8, theseguides have horizontal upper plates 71 on which the work holder supports64 are slidable. Adjacent plates 71 are spaced to provide guide slots 72through which extend spacing sleeves 73. These, together with washers74, are interposed between links 63 and the supports 64. The links,spacer sleeves, washers, and supports are connected by screws, whileheaded vertical pins 75 screw threaded to supports 64 rotatably connectthe work holders 21 to the supports. The spacer sleeves 73 constituteloose fitting keys in the slots 72 which prevent any substantialrelative rotation of the supports 64.

The work holders 21 have vertical bores 76 coaxial with pins 75 forreceiving the shanks of the workpieces, and

inclined side faces 77 which are designed to engage the opposite sidesof the body portions of the workpieces, as the latter are lowered intothe work holders to cam them into the predetermined angular relation,about the axes of their shanks, in which they are to be engaged with thecarriers 18 and 23. In order for them to engage both carriers in thesame relation, it is necessary to rotate the workpieces through 180during their forward travel in the conveyor 22. For this purpose teeth78 are provided around the work holders 21 and sets of teeth 79 and 81are provided on the guide structure, FIG. 1. Teeth 79 rotate each workholder 180 about its pin 75 during forward travel thereby, while teeth81 further rotate it 180 during its return travel. For accuratelylimiting these rotations to 180, and preventing accidental rotations,each carrier has two diametrically opposite recesses 82, FIG. 8. At theconclusion of each 180 rotation of the work holder, one

of these recesses is engaged by a spring-backed detent 83 I that isslidable in the related support 64.

Each work holder 21 must be aligned vertically with the recess 26 atstation I in carrier 13 at the same time that another work holder issimilarly aligned with the corresponding recess at station I of carrier23; and this relationship must be maintained when the slide 8 and thecolumn 9 are adjusted horizontally to compensate for changes in thediameters of cutters C1 and O2 respectively, caused by cutterresharpening or replacement, or to accommodate work gears of a diiferentdesign. For this purpose the box-like chain guide sections are maderelatively adjustable. The sections designated 84 and 85, adjacent thecarriers 18 and 23, are rigidly secured to brackets 86 and 87,respectively, which are rigid with slides 8 and 13 and rotatably supportthe discs'65 and 66. Referring I to FIG. 9, the arcuate guide shoe 69and the disc 67 are respectively carried by sections 88 and 89 which aresupported by bracket 86 for horizontal adjustment thereon,perpendicularly to cutter axis 3, FIG. 1. Such adjustment may be made byloosening or tightening horizontal screws 91 and 92 which are rotatablein bracket 86 and are screwthreaded respectively into guide sections 88and 89. After such adjustment these sections may be rigidly secured tothe bracket by tightening screws 93 which extend through threadedopenings in the sections and through elongated slots 94 in the bracket.

Guide sections 95 and 96, which respectively support guide shoe'78 anddisc 68, are adjustably supported by bracket 87 in substantially thesame manner that sections 88 and 89 are supported by bracket 86.Horizontal pivot pins 97, one of which is supported by sections 88, 89,and the other by sections 95 and 96, extend in the directions in whichthese sections are adjusted. These pins pivotally support straight guidesections 98 and 99 which constitute the base of U-shaped guide structureand respectively support the return portion of the conveyor betweenguide sections 95 and 88, and the forward portion of the conveyorbetween guide sections 89 and 96. The pivotal support enables thebracket 87, the guide sections 85, 95, 96, and the portions of theconveyor 22 supported thereby, to reciprocate vertically in unison withslide 13 and finishing work head 12. In adjusting the guide sections 88,89, 95, 96, the screws 91 and 92 may first be loosened and the workholders 21 nearest carriers 18 and 23 are brought into accurate verticalalignment with the work engaging to prevent undue loads on the conveyor22 and its supporting and guide means, two actuators for the conveyorare provided, one of them adjacent each carrier. Adjacent carrier 18there is the actuator 101 shown in detail in FIG. 10, comprisinghydraulic cylinder 182 mounted on bracket 86, FIG. 1. Piston 103 in thecylinder is rigidly connected to a slide 1114 supported by the cylinder.A puller-pawl 185 is pivoted to the slide by a pin 106, and is urged toits counterclockwise limit position about this pin by a spring-backedplunger 107. In this limit position the claw-shaped end of the pawl isengageable, as shown in broken lines in FIG. 10, with a work holder 21on the forward path of guide section 84. On each forward stroke of thepiston, to the left in FIG. 1 and to the right in FIG. 10, the pawl soengages a holder and advances it, and the conveyor, by one pitch, i.e.to move one work holder from station IV and bring the following workholder to this station. On each return stroke of the piston, camsurfaces 108 of the pawl ride over and engage behind the next workholder.

The actuator 109, FIGS. 1 and 11, comprises a cylinder 111 secured tobracket 87 and having reciprocable therein a piston 112 whose piston rodis rigidly connected by a head 113 to a guide rod 114 that is alsoslidable in the cylinder block. A pusher pawl 115 pivoted by a pin 116to head 113 is engageable, in its clockwise limit position, with a workholder 21 on the forward path of guide section 85; and surfaces 120 ofthe pawl are engageable with a workpiece W in the work holder. The pawlis urged clockwise by a torsion spring 117 which allows pivotal motionof the pawl to ride over a work holder, to a position therebehind,during each return stroke of the piston and pawl assembly 112, 115. Oneach forward stroke a work holder and the conveyor is advanced by onepitch of the conveyor.

The conveyor 17 has substantially the same pivoted link construction asthe conveyor 22, differing therefrom primarily in that the work holders16 are rigidly connected to parts which correspond to supports 64 inFIG. 8. The conveyor runs over guide discs 118 and 119 and arcuate guideshoes 121 and 122. Disc 118 and shoes 121, 122 are supported by a guidesection 123 and disc 119 by a guide section 124, these sections beingsimilar in construction to section 84 shown in FIG. 8, and section 123being rigidly mounted on an extension of bracket 86. Means not shown,similar to means 92-94 in FIG. 9, are provided to adjust section 124horizontally relative to section 123, in a direction perpendicular toaxis 3, for adjusting the tension of conveyor 17. An actuator 125 isprovided for the conveyor, this actuator being substantially like thosedesignated 109, 115 in FIG. 11, and including a cylinder 126 secured tothe guide section 123 and a pusher pawl 127 for engagement with workholders 16 and workpieces W.

The lower shanks of the workpieces are chucked on the work spindles 4,10 by means including an hydraulic chuck actuator 128, FIG. 13, in eachwork head 5, 12. Preferably the chucking apparatus is as disclosed incopending application Ser. No. 356,819, filed on even date recesses 26in these carriers at their stations IV and I respectively. Screw 91 ofguide sections 88 and the corresponding screw of section 95 may then beturned to adjust the tension of the return portion of conveyor 22 whilemaintaining section 98 substantially perpendicular to sections 84 and 85(to prevent binding at the pivots 97); and similarly screw 92 of section89 and the corresponding screw of section 96 may be turned to adjust thetension of forward portion of the conveyor while keeping section 99substantially perpendicular to sections 84 and 85.

- In order to accurately align the work holders 21 at station IV ofcarrier 18 and at station I of carrier 23, and

herewith by C. G. Braun and G. H. Howing. Simultaneously with chucking,the upper shank of the workpiece is engaged by a center 129, FIG. 12,which is aligned with the work spindle axis 6 or 11. The center iscarried by a guide rod 131, FIGS. 1, 2 and 12, reciprocable in a bracket132 that is adjustably secured to the work head, 5 or 12. Suchreciprocation is effected by a piston 133 in a cylinder 134 in thebracket, the rod of the piston being connected to guide rod 131 by aplate 135.

Referring to FIG. 13, the carrier actuating cylinders 53, 53' aresimultaneously controlled by a solenoid operated reversing valve 136connected to suitable hydraulic pressure and exhaust lines, not shown.The solenoid windings of the valve are controlled by electrical switches139 and 141 which are closed respectively when the work heads, 5, 12,reach and depart from loading position, the

- control of the valve by switch 139 being through a time delay switch142. Cylinders 102, 111, 126 of the conveyor actuators are similarlyconnected to the hydraulic lines by a solenoid reversing valve 143 alsocontrolled by switches 139 and 141; and the chuck and center actuatingcylinders 128, 134, are controlled by a solenoid reversing valve 144.One solenoid winding of this valve is controlled by switch 139 in serieswith a switch 145 that is closed only at the end of each cutting cycleof the machine. The other solenoid winding of the valve is controlled bya switch means 146 closed when racks 55, 55' of the carrier actuatorsconclude each work transfer stroke. Accordingly, in operation, whencutting is concluded, closing switch 145 and causing the work heads tomove to loading position, which closes switch 139, pressure is applied(a) to cylinders 128, 134, to dechuck the work and retract the centers129, (b) to cylinders 102, 111, 126, to cause the idle, return strokesof the conveyor actuators, and (c), with a slight delay, to cylinders53, 53, to effect a work-transfer cycle of carriers 18, 23. Switch means146 are closed at the conclusion of this cycle, to (d) cause cylinders128 and 134 to chuck and center the work, and the cutting cycle torestart by the work heads moving from loading position toward cuttingposition. This opens switch 139 and closes switch 141 so that pressureis applied (e) to cylinders 102, 111 and 126, to advance the conveyors17 and 22, and (f) to cylinders 53, 53', to effect the return strokes ofthe carrier actuating pistons.

The modification of the invention illustrated in FIGS. 14 to 23 isdesigned for bevel gears G having axial bores. It differs from the firstdescribed embodiment in the form and arrangement of (1) the means fordelivering work gears to the roughing carrier which transfers them toand from roughing work spindle, (2) the roughing and finishing carriersand the actuating means therefor, (3) the work holders of the conveyorbetween the roughing carrier and the finishing carrier, and (4) a meansfor st-ripping'work gears from the carriers. The parts of the machinewhich are essentially the same as parts of the modification shown inFIGS. 1 to 13, bear the same reference numerals.

Referring to FIG. 14, work gear blanks G are contained in a magazine 161at a higher level than conveyor 22, and pass by gravity through aninclined chute 162 to a recess 163, at bottom of the chute structure,beneath a carrier 164 adjacent work head 5. A gate 165 in the chute iscontrolled in a known manner in time with operation of the carrier, sothat one workpiece is delivered to the recess 163 at a time when thelatter is empty during each operating cycle of the carrier.

Referring to FIGS. 14, 15 and 16, the carrier comprises a plate 167moved along and about vertical axis 168 by an actuating mechanism,within housing 169, that is driven by a piston in cylinder 53 actingthrough rod 54, rack 55 and pinion 56. Plate 167 carries two pairs ofpivoted jaws, 171 and 172, each pair being adapted to grip a work gearin themanner shown in FIG. 16. Upon downward motion of the carrier, jaws171 engage a gear blank in recess 163, whose axis there is designated173; and jaws 172 engage a roughed gear on the work spindle whose axis 6is upright at this time. Upward motion of the carrier lifts the workgears, stripping the gear in jaws 172 from the work spindle. The carrierthen swings about axis 168, to its position shown in broken lines inFIG. 15, to align the blank in jaws 171 with axis 6 and the gear in jaws172 with a vertical axis 174 along which it is transferred to a workholder 175 on conveyor 22. Then by down motion of the carrier the blankis placed on the work spindle and the roughed gear in jaws 172 is placedon the conveyor; the chuck on the Work spindle is actuated to grip theblank; and the carrier rises, the jaws 171, 172 thereby being strippedfrom the workpieces. After the work head is then swung forwardly tocutting position about axis 7, the carrier returns, empty, to itsstarting position. During this return it retraces the path it followedin the work transfer part of its cycle.

The actuating mechanism for the carrier, illustrated in FIGS. 17 to 19,diifers from that in FIGS. 3 and 4 in the following respects: Pinion 56is fixed to vertical shaft 176 so that the cam 177 on the latter isoscillated through 360 during each reciprocation of rack 55. The Genevadriven member 178 keyed to the carrier shaft 179 has a single radialslot 181 engageable by pin 182 of the Geneva driver 183 on shaft 176.Fine angular positioning of the carrier for aligning the jaws with axes173, 6 and 174, is effected by an arm 184 that is secured to the upperend of shaft 179 and that has a bore 185, FIGS. 14 and 18, adapted forclose sliding fit with either of two angularly spaced guide pins 186 onhousing 169. The path of earn 177, developed into a plane in FIG. 19,includes two active sections, one of them between points 187 and 188 andthe other between points 189 and 187, and a dwell section between points188 and 189. The active sections each cause a reciprocation of thecarrier along its axis at a time when the pin 182 is disengaged fromradial slot 181; the dwell is effective to hold the carrier against suchaxial motion while the pin is engaged in the slot and is causing thecarrier to swing about its axis. This shape of the cam is different fromthat of cam 35, FIG. 3, which is as shown in dotted lines in FIG. 19,being designed to effect only one vertical reciprocation per worktransfer cycle.

The jaws 171 and 172, are essentially alike and are mounted on the plate167 in the same manner, as shown in FIGS. 15 and 16, and are pivoted bypins 191 to upstanding bifurcations 192 on a member 193 secured to plate167. Springs 194 acting between this plate and the jaws urge the latterabout their pivots into engagement with the work gear. The work-engagingsurfaces 195 of the jaws are so shaped as to cam apart, to receive orrelease a work gear. For centering and aligning the work gears on thecarrier a tapered center plunger 196 is slidable in a central verticalbore in member 193 and is pressed downwardly into bore 197 of the gearby a spring 198; and a plate 199, guided by a plurality of pins 201(only one of which is shown) secured to member 193, is presseddownwardly against the upper face 202 of the gear by springs 203supported by the pins 201. Adjacent the finishing work head, on theslide 13 (see FIG. 1) the machine illustrated in FIG. 14 also has acarrier, similar to carrier 164, FIG. 16, but of opposite hand, fordelivering rough cut gears to the finishing work spindle 10. Thiscarrier has stock dividing means associated with the delivering jaws172. These means comprise two spring-backed pins 210, FIG. 16, slidablein plate 199 and adapted to enter diametrically opposite or nearlyopposite tooth slots, to rotate the gear into the desired angularrelation to the carrier 164 as the gear is received by the jaws. Onlyone of the two pins 210 is shown.

The work holders 175, FIGS. 14 and 20, have pintles 204 for looselyentering the work gear bores 197, and are rigidly secured to links 63'of the conveyor 22. Slots 205 are provided in the peripheries of thework holders to receive the tips of the jaws 171 or 172, as indicated inFIG. 16, where a work holder is shown in broken lines. Each work holderhas a cylindrical surface 206 for engagement by a pivoted pawl 207 of anactuator 208, similar to actuators 101 and 109, which is provided foreffecting step-by-step advance of the conveyor adjacent the roughingwork head 5. A similar conveyor actuator, not shown, is providedadjacent the finishing Work head.

For coarse stock dividing gears on the work holders 175 approaching thefinish cutting station, the device shown in FIGS. 22 and 23 is provided.This device is mounted on the upper plates 71 of the conveyor guideadjacent axis 174' which corresponds to roughing station axis 174, FIG.14, in that it is the axis along which gears are transferred between theconveyor 22, 175, and the work carrier 164. It comprises convergingguides 209 mounted on a support 211 for aligning with axis 174' the axesof approaching workpieces G loosely held on supports 175 by pintles 204.After such alignment, the approaching gears are guided by and betweenparallel rails 212, 213 that are supported by guides 209. Rail 212 hastherealong several leaf spring fingers 214 and rack teeth 215 forengaging in tooth slots of each gear, as it approaches axis 174, androtating the gear into an angular position such that its tooth slots arealigned to receive stock dividing pins 210, FIG. 16, of the finishingstation carrier 164. 1

After finish cutting by cutter C-2, the finishing station carrierremoves the gears from the spindle and then discharges them from themachine, preferably through a chute similar to that shown at 25 inFlG. 1. The release of the gears from the carrier above such chute, andalso the release from roughing station carrier 164 of gears on axis 174,FIG. 14, is effected by plungers 216, FIG. 21, backed by springs 217 andslidably supported by brackets 218 secured to the upper plates 71 of theadjacent conveyor guide sections. The plungers are cammed radiallyoutward of the gears by back cones 219 of the latter as the carrierslower the gears into the discharge chute and along axis 174 and thenpressed inwardly by springs 217 to engage face cones 221 of the gears.The springs 217 are of suflicient strength relative to springs 194, FIG.16, to hold the gears down while the carriers are subsequently raised,to thereby strip the gears from the jaws.

We claim:

1. A tooth cutting machine having two substantially parallel workspindles, a work carrier adjacent each spindle arranged for angularindexing about an axis substantially parallel to the spindles to carryworkpieces successively to and from the spindles, an endless flexibleconveyor having work holders equally spaced therealong and arranged tocarry workpieces from one to the other of said carriers, means foractuating said carriers, and means for intermittently operating saidconveyor in time with actuation of the carriers, the conveyor upon eachsuch operation moving through a distance corresponding to the spacing ofthe work holders therealong which is such that upon each operation ofthe conveyor one work holder is brought to one carrier and another tothe other carrier, one such operation of the conveyor occurring betweensuccessive actuations of the carriers, the means for intermittentlyoperating said conveyor comprising a pair of ratcheting actuators forintermittently advancing the conveyor, said actuators being arranged toact on portions of the conveyor adjacent the respective work carriers,and means connecting said actuators for simultaneous operation.

2. A tooth cutting machine having two substantially parallel workspindles, a work carrier adjacent each spindle arranged for angularindexing about an axis substantially parallel to the spindles to carryworkpieces successively to and from the spindles, an endless flexibleconveyor having work holders equally spaced therealong and arranged tocarry workpieces from one to the other of said carriers, means foractuating said carriers, and means for intermittently operating saidconveyor in time with actuation of the carriers, the conveyor upon eachsuch operation moving through a distance corresponding to the spacing ofthe Work holders therealong which is such that upon each operation ofthe conveyor one work holder is brought to one carrier and another tothe other carrier, one such operation of the conveyor occurring betweensuccessive actuations of the carriers, said carriers having workpiecesupporting recesses .in the peripheries thereof, detent means forreleasably retaining said shanks in said recesses, and a stationary camadjacent said other one of said carriers for ejecting workpiecestherefrom by and during an angular indexing of the carrier which followsremoval of said workpieces from the adjacent spindle.

3. A tooth cutting machine having a pair of Work spindles, a Workcarrier adjacent each spindle arranged for angular indexing about andreciprocation along an axis parallel to the spindle to carry workpiecessuccessively to and from said spindle, a conveyor having spacedworkholders thereon for transferring workpieces from one carrier to theother, means for intermittently operating the conveyor and betweensuccessive such operations effect-ing reciprocations and angularindexing of the carriers, with a reciprocation preceding each indexing,the reciprocation serving to place workpieces on the work spindles andwork holders, and the indexing serving to carry workpieces from onespindle to the work holders and from the latter to the other spindle,said carriers having two sets of spring-closed jaws for respectivelyengaging a workpiece being received by the carrier and a workpiece onthe adjacent work spindle during one stroke of one reciprocation of thecarrier, and means engaging workpieces in one set of jaws, subsequent toangular motion of the carrier to carry such workpieces from the spindleto the point of discharge from the carrier, to strip the workpieces fromthe jaws during an opposite stroke of reciprocation of the carrier.

4. A tooth cutting machine having two substantially parallel workspindles, a work carrier adjacent each spindle arranged to transferworkpieces successively to and from the spindle, an endless flexibleconveyor having work holders equally spaced therealong and arranged forintermittent motion to carry workpieces from one to the other of saidcarriers, first and second guides respectively determining the two pathsof said endless conveyor between said carriers, and adjusting means foreach of said guides to vary the lengths of said paths, to enable thesimultaneous registration of work holders with both carriers.

5. A machine according to claim 4 in which said guides are so arrangedthat said two paths of said endless conveyor are each of substantiallyU-shape, with one such U-shaped path substantially inside of the other,and said paths being connected at the open ends of their U-shapes bysemi-circular portions which are tangential to the circular paths ofmotion workpieces on said carriers, and said adjusting means beingarranged for adjusting the lengths of the legs of said U-shaped paths.

6. A machine according to claim 5 having a rotary cutter adjacent eachwork spindle, and a cutter spindle supporting both of said cutters, saidlegs of said U-shaped paths being perpendicular to the axis of saidcutter spindle.

7. A machine according to claim 6 in which each work carrier and thework spindle related thereto is mounted on a support which is adjustablerelative to the cutter spindle in a direction parallel to said legs.

8. A tooth cutting machine having two work spindles and an endlessflexible conveyor for transferring workpieces between said spindles, amember supporting each spindle for rotation and means for reciprocatingone member relative to the other in a direction parallel to the axes ofsaid spindles in the work loading and unloading positions of the latter,and a guide for the conveyor com prising a terminal guide section,adjacent each member. which is secured to the member and supports thetwo portions of the conveyor between the spindles substantially in aplane perpendicular to said direction, and an intermediate guidesection, for supporting portions of the conveyor between said terminalguide sections, having articulated connections to said terminal guidesections to accommodate the reciprocation of the slide member.

9. A machine according to claim 8 in which both portions of said endlessconveyor are of substantially U- shape, with one such U-shaped portioninside of the other and connected at the open ends of their U-shapes bysubstantially semicircular portions, and with the base of each Usubstantially straight and connected by arcuate portions to the legs ofthe U, said intermediate guide section supporting the portions of theconveyor at the substantially straight base of the U, and saidarticulated con- 11 nections comprising pivots whose axes substantiallyparallel said legs.

10. A tooth cutting machine having a pair of substantially parallelvertical work spindles on opposite sides thereof, tooth cutting meansforward of said spindles, a work carrier adjacent each spindle arrangedfor angular indexing about and reciprocation along an axis substantiallyparallel to the spindle to carry workpieces successively to and from thespindle, and endless flexible conveyor having work holders spacedtherealong and arranged to carry work-pieces from one to the other ofsaid carriers, guide means for said conveyor extending substantiallyhorizontally along the sides and around the back of the machine,providing two guide paths of said conveyor each of which is ofsubstantially U-shape, with one U-shaped path substantially inside theother, and said paths being connected at the open ends of their U-shapesby semi-circular portions adjacent the respective carriers, and meansfor intermittently operating said conveyor in time with actuation of thecarriers, the conveyor upon each such operation moving through adistance corresponding to the spacing of the work holders therealongwhich is such that upon each operation of the conveyor one work holderis brought to one carrier and another to the other carrier, one suchoperation of the conveyor occurring between successive actuations of thecarriers.

References Cited UNITED STATES PATENTS 2,376,161 5/1945 Maud et a174-422 2,736,238 2/ 1956 Moncrietf 901 2,773,426 12/1956 Fowler et al.901 2,995,068 8/1961 Mills 901 FOREIGN PATENTS 1,074,367 1/ 1960Germany.

LEONIDAS VLACHOS, Primary Examiner.

1. A TOOTH CUTTING MACHINE HAVING TWO SUBSTANTIALLY PARALLEL WORKSPINDLES, A WORK CARRIER ADJACENT EACH SPINDLE ARRANGED FOR ANGULARINDEXING ABOUT AN AXIS SUBSTANTIALLY PARALLEL TO THE SPINDLES TO CARRYWORKPIECES SUCCESSIVELY TO AND FROM THE SPINDLES, AN ENDLESS FLEXIBLECONVEYOR HAVING WORK HOLDERS EQUALLY SPACED THEREALONG AND ARRANGED TOCARRY WORKPIECES FROM ONE TO THE OTHER OF SAID CARRRIERS, MEANS FORACTUATING SAID CARRIERS, AND MEANS FOR INTERMITTENTLY OPERATING SAIDCONVEYOR IN TIME WITH ACTUATION OF THE CARRIERS, THE CONVEYOR UPON EACHSUCH OPERATION MOVING THROUGH A DISTANCE CORRESPONDING TO THE SPACING OFTHE WORK HOLDERS THEREALONG WHICH IS SUCH THAT UPON EACH OPERATION OFTHE CONVEYOR ONE WORK HOLDER IS BROUGHT TO ONE CARRIER AND ANOTHER TOTHE OTHER CARRIER, ONE SUCH OPERATION OF THE CONVEYOR OCCURRING BETWEENSUCCESSIVE ACTUATIONS OF THE CARRIERS, THE MEANS FOR INTERMITTENTLYOPERATING SAID CONVEYOR COMPRISING A PAIR OF RATCHETING ACTUATORS FORINTERMITTENTLY ADVANCING. THE CONVEYOR, SAID ACTUATORS BEING ARRANGED TOACT ON PORTIONS OF THE CONVEYOR ADJACENT THE RESPECTIVE WORK CARRIERS,AND MEANS CONNECTING SAID ACTUATORS FOR SIMULTANEOUS OPERATION.